Arithmetic and control unit



FIG. 1 is a front elevational view of an arithmetic and control unit showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a left side elevational view thereof; and,

FIG. 7 is another top plan view thereof wherein the disc tray portion is in the open position. The disc tray portion in broken lines is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for an arithmetic and control unit, as shown and described. 